Philippe Coutinho enjoyed a dream debut for Aston Villa as he came off the bench to inspire a 2-2 comeback draw at home to Manchester United, scoring a late equaliser.
Rafa Benitez's troubles at Everton continued as they suffered a 2-1 loss at Norwich City, who moved off the bottom of the table with their third win of the campaign.
Newcastle United conceded a late equaliser in a 1-1 draw at home to Watford, missing the chance to escape the drop zone.
City's 12th win in a row, thanks to a 70th minute solo strike from Kevin De Bruyne, continues their charge towards a successful defence of their title but manager Pep Guardiola was quick to dismiss such talk.
Third-placed Liverpool are 14 points behind City but have two games in hand, including Sunday's visit of Brentford.
"(The players) are going to listen to me that it is not true when people say it is over. In January it is impossible it is over," Guardiola said.
"If Liverpool win the games in hand, it's eight points. Now my job is to put in the brains of my players to not believe what the people say. But 12 wins - 36 points from 36 - hats off to them," the Spaniard added.
DE BRUYNE WINNER
After a first half which saw few clear chances, other than Jack Grealish being foiled by Chelsea keeper Kepa Arrizabalaga, Chelsea had an opportunity to take the lead after the break but Romelu Lukaku's shot was well saved by Ederson.
City were well in control of the game for large spells and took the points after De Bruyne burst away from N'golo Kante and beat Kepa with a superb shot into the far corner.
Chelsea boss Thomas Tuchel was critical about the performance of his attack, in particular Lukaku, who recently had to apologise for an interview with Italian media in which he said he was unhappy with the German coach's system.
"He had many ball losses without any pressure, many ball losses in very promising circumstances," Tuchel told reporters.
"He had a huge chance. We want to serve him, but he is part of the team, and the performance up front, particularly in the first half, we can do much, much better."
Manchester United interim manager Ralf Rangnick described the opening 30 minutes at Villa as the best since he took charge, but he was left struggling to find positives after goals by Jacob Ramsey and Coutinho cancelled out Bruno Fernandes's double which had United 2-0 up with 20 minutes left.
"It feels more like a defeat," the German said as his side remained in seventh place.
Norwich threw themselves a lifeline in their battle against relegation but sucked Everton into the mire thanks to a victory at Carrow Road that heaped pressure on Benitez.
An own goal by Michael Keane and Adam Idah's close-range finish in the space of two first half minutes broke Norwich's goal famine that had spanned six league games.
Richarlison halved the deficit on the hour to set up a tense finale but Norwich hung on, with Everton's travelling fans venting their anger at Benitez.
Norwich moved up to 18th place with 13 points, six behind 15th-placed Everton who have lost nine of their last 12 league games but have two matches in hand on the Canaries.
Newcastle United had hoped the addition of 25 million pound ($34.18 million) New Zealand striker Chris Wood, signed from relegation rivals Burnley in midweek, would boost their survival chances but they had to settle for a point at home to Watford.
Allan Saint-Maximin put the hosts in front four minutes after the break with a brilliant solo effort but Watford's Joao Pedro popped up to head home brilliantly in the 88th minute.
Newcastle are in 19th on 12 points, one ahead of bottom club Burnley, who have three games in hand of United after their fixture at home to Leicester City was postponed due to COVID-19.
"We've damaged ourselves to a point, but you always have an opportunity to bounce back," Newcastle boss Eddie Howe said.
Eighth-placed Wolverhampton Wanderers continued their good form with a 3-1 home win over Southampton thanks to goals from Raul Jimenez, Conor Coady and Adama Traore.